package shreder

import (
	"encoding/binary"
	"fmt"

	"github.com/gagliardetto/solana-go"
	"github.com/shopspring/decimal"
)

var flasProgramID = solana.MustPublicKeyFromBase58("FLASHX8DrLbgeR8FcfNV1F5krxYcYMUdBkrP1EPBtxB9")
var (
	flasBuyTokensIXs = [][]byte{
		{0x00, 0x01, 0x21},
		{0x00, 0x01, 0x1b},
	}
	flasSellTokensIXs = [][]byte{
		{0x01, 0x01, 0x1a},
	}
	flasAmmBuyTokensIXs = [][]byte{
		{0x00, 0x02, 0x1f},
		{0x00, 0x02, 0x02},
	}
	flasAmmSellTokensIXs = [][]byte{
		{0x01, 0x02, 0x1f},
		{0x01, 0x02, 0x02},
	}
	flasBonkBuyTokensIXs = [][]byte{
		{0x00, 0x02, 0x07},
	}
	flasBonkSellTokensIXs = [][]byte{
		{0x01, 0x02, 0x07},
	}
)

type flasArgs struct {
	Amount1     uint64
	Amount2     uint64
	Placeholder [3]uint8
}

func decodeFlasArgs(data []byte) (flasArgs, error) {
	if len(data) < 20 {
		return flasArgs{}, fmt.Errorf("data too short for args flas instruction, len: %d", len(data))
	}
	return flasArgs{
		Amount1:     binary.LittleEndian.Uint64(data[1:9]),
		Amount2:     binary.LittleEndian.Uint64(data[9:17]),
		Placeholder: [3]uint8{data[17], data[18], data[19]},
	}, nil
}

func matchFlasMethod(data []byte, methods [][]byte) bool {
	for _, method := range methods {
		if matchMethod(data, method) {
			return true
		}
	}
	return false
}

func parseFlasInstruction(tx VersionedTransaction, instructionIndex int) (TxSignalBatch, error) {
	if instructionIndex >= len(tx.Instructions) {
		return nil, fmt.Errorf("instruction index out of bounds")
	}

	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Data) == 0 {
		return nil, fmt.Errorf("data is empty")
	}
	if len(instruction.Data) == 10 && instruction.Data[0] == 1 {
		return nil, nil
	}
	if len(instruction.Data) < 20 {
		return nil, fmt.Errorf("data too short for args flas instruction, len: %d", len(instruction.Data))
	}
	methodData := instruction.Data[17:20]
	var (
		err      error
		txSignal *TxSignal
	)
	if matchFlasMethod(methodData, flasBuyTokensIXs) {
		txSignal, err = parseFlasBuy(tx, instructionIndex)
	} else if matchFlasMethod(methodData, flasSellTokensIXs) {
		txSignal, err = parseFlasSell(tx, instructionIndex)
	} else if matchFlasMethod(methodData, flasAmmBuyTokensIXs) {
		txSignal, err = parseFlasAmmBuy(tx, instructionIndex)
	} else if matchFlasMethod(methodData, flasAmmSellTokensIXs) {
		txSignal, err = parseFlasAmmSell(tx, instructionIndex)
	} else if matchFlasMethod(methodData, flasBonkBuyTokensIXs) {
		txSignal, err = parseFlasBonkBuy(tx, instructionIndex)
	} else if matchFlasMethod(methodData, flasBonkSellTokensIXs) {
		txSignal, err = parseFlasBonkSell(tx, instructionIndex)
	}
	if txSignal != nil {
		return TxSignalBatch{txSignal}, err
	}
	return nil, err
}

func parseFlasAmmSell(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 10 {
		return nil, fmt.Errorf("accounts too short")
	}

	mint, err := tx.GetAccount(int(instruction.Accounts[9]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}

	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}
	token0Amount := formatTokenAmount(args.Amount1)
	token0AmountUint64 := args.Amount1
	if len(instruction.Accounts) == 52 {
		token0Amount = decimal.Zero
		token0AmountUint64 = 0
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      mint.String(),
		Token1Address:      wsolMint,
		Token0Amount:       token0Amount,
		Token1Amount:       formatSolAmount(args.Amount2),
		Program:            "PumpAMM",
		Event:              "sell",
		IsToken2022:        false,
		IsMayhemMode:       false,
		ExactSOL:           false,
		Block:              tx.Block,
		Token0AmountUint64: token0AmountUint64,
		Token1AmountUint64: args.Amount2,
	}, nil
}

func parseFlasAmmBuy(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 10 {
		return nil, fmt.Errorf("accounts too short")
	}

	mint, err := tx.GetAccount(int(instruction.Accounts[9]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}

	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      mint.String(),
		Token1Address:      wsolMint,
		Token0Amount:       decimal.Zero,
		Token1Amount:       formatSolAmount(args.Amount1),
		Program:            "PumpAMM",
		Event:              "buy",
		IsToken2022:        false,
		IsMayhemMode:       false,
		ExactSOL:           true,
		Block:              tx.Block,
		Token0AmountUint64: 0,
		Token1AmountUint64: args.Amount1,
	}, nil
}

func parseFlasSell(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 11 {
		return nil, fmt.Errorf("accounts too short")
	}

	mint, err := tx.GetAccount(int(instruction.Accounts[10]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}

	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      mint.String(),
		Token1Address:      wsolMint,
		Token0Amount:       formatTokenAmount(args.Amount1),
		Token1Amount:       formatSolAmount(args.Amount2),
		Program:            "Pump",
		Event:              "sell",
		IsToken2022:        false,
		IsMayhemMode:       false,
		Block:              tx.Block,
		Token0AmountUint64: args.Amount1,
		Token1AmountUint64: args.Amount2,
	}, nil
}

func parseFlasBuy(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 11 {
		return nil, fmt.Errorf("accounts too short")
	}

	mint, err := tx.GetAccount(int(instruction.Accounts[10]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}
	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      mint.String(),
		Token1Address:      wsolMint,
		Token0Amount:       formatTokenAmount(args.Amount2),
		Token1Amount:       formatSolAmount(args.Amount1),
		Program:            "Pump",
		Event:              "buy",
		IsToken2022:        false,
		IsMayhemMode:       false,
		ExactSOL:           true,
		Block:              tx.Block,
		Token0AmountUint64: args.Amount2,
		Token1AmountUint64: args.Amount1,
	}, nil
}

func parseFlasBonkBuy(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 17 {
		return nil, fmt.Errorf("accounts too short")
	}

	base, err := tx.GetAccount(int(instruction.Accounts[15]))
	if err != nil {
		return nil, err
	}
	quote, err := tx.GetAccount(int(instruction.Accounts[16]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}

	if !quote.Equals(wrappedSOL) {
		// just ignore this
		return nil, nil
	}

	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      base.String(),
		Token1Address:      wsolMint,
		Token0Amount:       formatTokenAmount(args.Amount2),
		Token1Amount:       formatSolAmount(args.Amount1),
		Program:            "RaydiumLaunchLab",
		Event:              "buy",
		ExactSOL:           true,
		Block:              tx.Block,
		Token0AmountUint64: args.Amount2,
		Token1AmountUint64: args.Amount1,
	}, nil
}

func parseFlasBonkSell(tx VersionedTransaction, instructionIndex int) (*TxSignal, error) {
	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Accounts) < 17 {
		return nil, fmt.Errorf("accounts too short")
	}

	base, err := tx.GetAccount(int(instruction.Accounts[15]))
	if err != nil {
		return nil, err
	}
	quote, err := tx.GetAccount(int(instruction.Accounts[16]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[1]))
	if err != nil {
		return nil, err
	}

	if !quote.Equals(wrappedSOL) {
		// just ignore this
		return nil, nil
	}

	args, err := decodeFlasArgs(instruction.Data)
	if err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return &TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "flas",
		Maker:              user.String(),
		Token0Address:      base.String(),
		Token1Address:      wsolMint,
		Token0Amount:       formatTokenAmount(args.Amount1),
		Token1Amount:       formatSolAmount(args.Amount2),
		Program:            "RaydiumLaunchLab",
		Event:              "sell",
		Block:              tx.Block,
		Token0AmountUint64: args.Amount1,
		Token1AmountUint64: args.Amount2,
	}, nil
}